Merge epotemkin@bk-internal.mysql.com:/home/bk/mysql-4.1

into moonbone.local:/work/14186-bug-4.1-mysql

mysql-test/r/update.result

@@ -337,3 +337,11 @@ a	b
 22	3
 23	3
 drop table t1;
+create table t1 (f1 date not null);
+insert into t1 values('2000-01-01'),('0000-00-00');
+update t1 set f1='2002-02-02' where f1 is null;
+select * from t1;
+f1
+2000-01-01
+2002-02-02
+drop table t1;

mysql-test/t/update.test

@@ -260,5 +260,14 @@ update t1 set a=a+11,b=2 order by a limit 3;
 update t1 set a=a+12,b=3 order by a limit 3;
 select * from t1 order by a;
 
+drop table t1;
+
+#
+# Bug#14186 select datefield is null not updated
+#
+create table t1 (f1 date not null);
+insert into t1 values('2000-01-01'),('0000-00-00');
+update t1 set f1='2002-02-02' where f1 is null;
+select * from t1;
 drop table t1;
 # End of 4.1 tests

sql/sql_select.cc

@@ -69,8 +69,6 @@ static int return_zero_rows(JOIN *join, select_result *res,TABLE_LIST *tables,
 			    SELECT_LEX_UNIT *unit);
 static COND *optimize_cond(THD *thd, COND *conds,
 			   Item::cond_result *cond_value);
-static COND *remove_eq_conds(THD *thd, COND *cond, 
-			     Item::cond_result *cond_value);
 static bool const_expression_in_where(COND *conds,Item *item, Item **comp_item);
 static bool open_tmp_table(TABLE *table);
 static bool create_myisam_tmp_table(TABLE *table,TMP_TABLE_PARAM *param,
@@ -4615,7 +4613,7 @@ optimize_cond(THD *thd, COND *conds, Item::cond_result *cond_value)
   COND_FALSE always false	( 1 = 2 )
 */
 
-static COND *
+COND *
 remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value)
 {
   if (cond->type() == Item::COND_ITEM)

sql/sql_select.h

@@ -457,3 +457,4 @@ bool cp_buffer_from_ref(THD *thd, TABLE_REF *ref);
 bool error_if_full_join(JOIN *join);
 int report_error(TABLE *table, int error);
 int safe_index_read(JOIN_TAB *tab);
+COND *remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value);

sql/sql_update.cc

@@ -70,7 +70,7 @@ int mysql_update(THD *thd,
   ha_rows	updated, found;
   key_map	old_used_keys;
   TABLE		*table;
-  SQL_SELECT	*select;
+  SQL_SELECT	*select= 0;
   READ_RECORD	info;
   TABLE_LIST    *update_table_list= ((TABLE_LIST*)
 				     thd->lex->select_lex.table_list.first);
@@ -131,11 +131,19 @@ int mysql_update(THD *thd,
     DBUG_RETURN(-1);				/* purecov: inspected */
   }
 
+  if (conds)
+  {
+    Item::cond_result cond_value;
+    conds= remove_eq_conds(thd, conds, &cond_value);
+    if (cond_value == Item::COND_FALSE)
+      limit= 0;                                   // Impossible WHERE
+  }
   // Don't count on usage of 'only index' when calculating which key to use
   table->used_keys.clear_all();
-  select=make_select(table,0,0,conds,&error);
-  if (error ||
-      (select && select->check_quick(thd, safe_update, limit)) || !limit)
+  if (limit)
+    select=make_select(table,0,0,conds,&error);
+  if (error || !limit ||
+      (select && select->check_quick(thd, safe_update, limit)))
   {
     delete select;
     free_underlaid_joins(thd, &thd->lex->select_lex);